It is possible "streetable" has different definition to me. A lot of people like a choppy idle on their street cars. I did explain to engine builder the use of the car, weight, rear gear, trans, tire size, etc. In their defense, it does have enough vacuum to run power brakes. The builder was Muscle Motors, who came very recommended on this forum when I was asking around. The dyno run sheet shows total timing of 36. I don't think it has initial timing. My mechanic did the install, and I have as much confidence in him and his abilities as I do in any mechanic. He does excellent work and is very knowledgable. That doesn't mean the timing or something else doesn't need to be tweaked though, or that the addition of something like an X pipe as suggested wouldn't help. I hadn't thought of an X pipe. I want to have some info written down when I talked to him so I don't waste any of his time. I will see what he has to say. Today I checked the firing order just to be sure. there wasn't a loose wire or crossed wires (I doubted it but easy to check). I figured it runs too good to have that issue, but it idles like it might have. Thx.